Unintentional injury has been a leading cause of death among people aged 1 to 44, and has been the fifth leading cause of death overall in the United States. In a 2004 report, unintentional injuries at home resulted in nearly 20,000 deaths and 21 million medical visits, with death from choking and suffocation ranked fourth among the cause of unintentional home injury. In addition to home choking incidents, where for children there are generally at least as many resulting from ingested toys as for food products being eaten, there are many choking incidents occurring at restaurants and other locations.
Medical devices being usable to affect the respiration of a patient or a person in distress may be found dating back very early in the art, including, for example, the 1919 “Respirating Device” of U.S. Pat. No. 1,371,702 to Lyon. But these early devices were adapted to provide a mechanical means of stimulating artificial respiration by causing lung movement through the introduction of air and/or oxygen flowing thereto and therefrom, in correspondence with the normal capacity of the person's lungs. However, such devices eventually were adapted to provide a means of supplying a negative pressure to a person's airway in order to induce the removal of a mass of food lodged therein, to relieve choking and prevent death, which occurs frequently in such cases.
One such device is found in U.S. Pat. No. 4,971,0533 to Tarrats for a “Suction Mask to Relieve Choking.” The Tarrats device comprises a moveable piston disposed within a cylinder, and with an airway in communication with the cylinder and extending through a mask that is sealable upon a victim's mouth. The piston is spring loaded to drive it to one end of the cylinder. The spring biasing may be overcome manually to move the piston into a ready position, where it may be releasably secured using a pivotable lever. When a choking victim requires assistance, the airway of the device may be inserted into his/her throat, with the mask sealing upon the person's face, and when the lever is released, the spring drives the piston to the opposite end of the cylinder, creating a vacuum to draw out the mass of food from where it is lodged. However, one major drawback of the Tarrats device is that the vacuum pressure must build up over time as the piston moves within the cylinder. Removal of a lodged mass is far more effective when a sustained vacuum pressure may be applied instantaneously.
Another drawback of the Tarrats suction device is the method of attempting to control the amount of air in the chamber, so as to be appropriate for the size of the victim. Tarrats uses a spring biased lever mounted to the housing that may engage a each of series of square grooves, but this requires that the good Samaritan seeking to use the device on a victim or the victim seeking to use the device upon themselves must simultaneously hold the device while depressing the lever to release the piston, to then pull the piston from the chamber to create the vacuum pressure. The awkwardness of the arrangement would hamper operation of the device in the typical choking scenario where the speed in using and possibly reusing the device a second time are critical for the health and life of the victim. This awkward arrangement furthermore does not correlate the stroke of the piston with the volume of vacuum pressure created, so as to inform the user that the piston is properly positioned for that particular sized choking victim.
Similarly, U.S. Pat. No. 5,609,149 to Takach discloses an “Anti-Choke Device” in which a plunger is manually driven to create a vacuum pressure, but where the plunger is resilient and flexible to be responsive through deflection to prevent excessive vacuum, and thereby prevent injury such as a collapsed lung. However, Takach states that “a swift depression of the plunger induces strong partial vacuum which is useful in clearing a lodged obstruction from the throat.” Therefore, Takach suffers from the same drawback as Tarrats, in that the vacuum is not instantaneously applied, and conversely relies upon “swift” action by the person striving to provide aid to the choking victim.
U.S. Pat. No. 6,478,770 to Litkouhi, discloses a device that significantly improves upon the prior art by utilizing a sealed vacuum container as a source of negative pressure in creating an instantaneous and sustained pressure drop “to overcome the forces of weight and frictional engagement between the bolus and the contiguous tissue against which the bolus is lodged.” Although the device is very well adapted to serve effectively in removal of a lodged mass by a person carefully rendering the aid, where an attempt to operate the device is rushed and/or performed clumsily such that the attempt to dislodge the mass is unsuccessful, ready access to another vacuum canister is required to repeat the procedure. A second replacement canister may not be readily available, and may not be easily inserted in the device in order to repeat the procedure. Also, it may be appreciated that a canister being installed within a device may lose vacuum pressure when it is stored for a significant time, and may thus require periodic inspections and/or servicing. The device of the present invention provides improvements and advantages over the prior art as hereinafter described.